Environmental cues used in upstream orientation by Parameletus chelifer and P. minor (Ephemeroptera) nymphs; an experimental study

摘要: Experiments using a plexiglass Y -maze fluviarium showed that nymphs of Parameletus chelifer and minor each used different environmental cues to orient. P. reacted pH while were very sensitive concentration dissolved organic matter. The capacity detect these water quality differences was lost as soon the reached seasonally submerged areas suitable for growth at margin river. When both species had their growing areas, temperature became crucial cue orientation.